After 25 hours in the garage my horn now works, well one of them anyway!
Tomorrow night I should have the headlights and front indicators wired up and the fuse box and relays finalised.
Leaving the dash wiring and the rear light wiring until the body work and tunnel is fitted although it will all be tested beforehand.
All the steering column is wired up along with the mx5 brake switch and instrument cluster.
I've made the wiring loom so that is can be unplugged from the engine loom for when I fit another engine. I've also used the mx5 wiring diagrams so that I can easily, lol, find faults in the future.